Question

Cos(45+30)=cos45.cos30-sin45.sin30

Answer 1

Step-by-step explanation:

cos (45+30) = cos45.cos30 - sin45.sin30

(1/√2 + √3/2) = 1/√2 * √3/2 - 1/√2 * 1/2

(1 + √3)/2 = √3/4 - 1/2√2

(1 + √3)/2 = (√3 - √2)/4

(1 + √3)/2 = 1/4

1 + √3 = 1/2